Apparatus for repositioning discrete articles

ABSTRACT

Apparatus for changing the spacing between articles of a moving array of discrete articles includes transfer means mounted for orbiting along a closed orbital path passing through a receiving zone and a discharge zone. The orbital radius of the transfer means is adjustable to provide an orbital radius in the discharge zone which is different from that in the receiving zone. The transfer means are maintained in fixed, equal angular distances between them along the orbital path whereby the orbital path distance between adjacent transfer means is different in the discharge zone from that in the receiving zone thereby resulting in a different spacing between adjacent articles in the discharge zone from that in the receiving zone. Two or more orbital spacer means may be utilized in tandem to provide the change in spacing in stages. A method of changing the spacing between discrete articles of an array of articles is disclosed and include moving the articles along a closed, non-circular orbital path between a receiving zone and a discharge zone and maintaining different orbital radii in the receiving and discharge zones whereby the orbital path distance between articles is changed between the receiving and discharge zones.

BACKGROUND OF THE INVENTION

1. Field Of The Invention

The present invention is concerned with a method and apparatus forrepositioning discrete articles such as segments cut transversely from acontinuous moving web of material. For example, the present inventionhas utility with respect to repositioning discrete abutting segments ofan absorbent material cut from a continuously moving web of thematerial, to form a spaced-apart array upon a continuously moving web ofsubstrate material. Such technique may be utilized in the manufacture ofdisposable diapers, training pants and incontinence control garmentsgenerally.

Articles such as disposable diapers are generally made with aliquid-impervious backing sheet on which absorbent pads are positionedand covered by a liquid-pervious topsheet, the resulting compositematerial being out into discrete articles. In many cases it is desiredto place the discrete absorbent pads in a spaced-apart location onto theliquid-impervious backing sheet (or onto the liquid-pervious frontsheet), which serves as the substrate upon which the absorbent pads areplaced. However, the discrete absorbent pads are usually cut from acontinuously moving web of the absorbent material or material formed inplace, which produces a moving array of pads in an abuttingrelationship. Consequently, a means for placing the discrete absorbentpads onto the substrate web with a selected spacing between adjacentwebs is required. In other applications, it may be desired to reversethe procedure, i.e., to place individual ones of an array ofspaced-apart articles into continuous abutting array or to change thespacing between adjacent articles from one distance to another distance.

2. Description Of Related Art

U.S. Pat. No. 3,386,558 discloses a feeder mechanism in which a devicehaving fixed, radially extending arms is cam driven so that, as thedevice rotates, pneumatic suction cup gripping means at the ends of thearms travel along the path indicated in FIG. 2 for removing foldedcarton blanks 5 from a hopper 3 and depositing them atop stackedcontainers C moving along a conveyor belt 6. Rotationally eccentricmovement is provided to the means 19 which carries the fixed armsthereon.

U.S. Pat. No. 3,834,522 shows a transfer machine comprising a turrethaving a plurality of radially translatable carriages mounted thereon,which carriages are fitted with a suction cup 46 (FIG. 2) for gripping acontainer. A cam track (85 in FIG. 4) moves the carriages radiallyoutwardly during rotation so as to enable the suction cups to grip thecontainer at the unloading station, then retracts radially inwardly fortransporting the container, and then moves radially outwardly to feedthe container into the stacking device. The turret provides forintermittent movement between the stations to allow sufficient dwelltime for the freshly printed containers to dry.

U.S. Pat. No. 3,494,001, shows apparatus and method for making sanitarynapkins and discloses at column 10, line 58 et seq and FIGS. 11 and 12,the use of paired rolls operating at different peripheral speeds so asto separate individual articles 116 passing therethrough.

U.S. Pat. No. 3,827,545 concerns method and apparatus for changing thespacing between discrete, flexible web products and utilizes, asillustrated in FIGS. 1 and 3a-3d, a variable-speed pinch roll 14positioned between respective conveyor belts 12 and 16, which operate atdifferent speeds. The peripheral speed of the rolls comprising pinchroll 14 is varied between the respective speeds of conveyor belts 12 and16. The patentee refers to positive control being exercised on thetransferred object (column 7, lines 19-20).

U.S. Pat. No. 3,847,273 discloses a transfer means comprising a rotatingdrum having radially extending arms which carry gripper means fororbiting about the drum axis of rotation, as illustrated in FIG. 1. Theradial arms 26 are constant radius arms which rotate about their ownaxes to pivotably turn articles 12. Consequently, changes in spacingbetween adjacent articles are effected only to the extent of thedifference between the length and width of the individual transferredarticles.

U.S. Pat. No. 4,394,898 discloses method and apparatus for providingbalanced stacks of diapers by turning alternately dispensed diapers 90°to the right and the remaining alternately dispensed diapers 90° to theleft, so that 180°rotation is provided between adjacent diapers. Arotating drum having fixed, radially extending arms carrying pads whichengage the dispensed diapers is provided. The arms rotate about theirown axes.

French Pat. No. 2,490,601 shows a rotating turret 15 equipped with fixeddiameter radial arm and adapted to remove individual articles from astack 5a thereof to place them onto a conveyor belt 1.

U.S. Pat. No. 3,374,752 shows a transplanter for handling papercylinders containing seedlings which are transferred from a conveyorbelt 10 to members 22 mounted for rotation so as to deposit the seedlingcylinder into a furrow opened by a plow blade ("opener") 3. The members22 remain at a constant radial distance from the axis of rotation.

Various types of transfer mechanisms are exemplified in U.S. Pat. Nos.3,887,605; 4,164,996 and 4,471,865 and in French Pat. No. 1,113,360 andJapanese Patent Publication No. 55-135026.

U.S. Pat. No. 4,578,133 entitled "Method And Apparatus For ApplyingDiscrete Strips To A Web Of Material"discloses radially extending andretracting shoes employed to transfer segments of elastic stripsdispensed at one linear speed onto a continuous web traveling at adifferent linear speed. A change in the orbital radius of the shoesduring their traverse of the orbital path changes the orbital path speedof the shoe to accommodate the different linear speeds.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided apparatus forchanging the spacing between articles of a moving array of discretearticles, the apparatus comprising at least one spacer means comprising:an orbital drive means having transfer means mounted thereon, forexample, on radially translatable supports carried by the orbital drivemeans, for orbiting of the transfer means along a closed orbital pathpassing through a receiving zone and a discharge zone; gripper means onthe transfer means effective to grasp discrete articles in the receivingzone and to release the discrete articles in the discharge zone; andradius-adjusting means operatively connected to the transfer means toselectively adjust the orbital radius thereof between a receiving zoneradius and a discharge zone radius which is different from the receivingzone radius, whereby the closed orbital path is a non-circular orbitalpath, and the orbital path distance between adjacent transfer means inthe receiving zone is different from the orbital path distance betweenadjacent transfer means in the discharge zone.

In one aspect of the invention, the apparatus comprises two or more ofthe spacer means respectively positioned with the discharge zone of therelatively upstream spacer means being located proximate to thereceiving zone of the adjacent downstream spacer means.

In another aspect of the invention, the radius-adjusting means isdimensioned and configured to adjust the orbital radius to provide adischarge zone radius which is larger than the receiving zone radius,whereby the orbital path distance between adjacent transfer means of agiven spacer means is greater in its discharge zone than in itsreceiving zone. When two or more spacer means are used, the orbital pathdistance between adjacent transfer means in the final (downstream)spacer means may be greater than that in the initial (upstream) spacermeans.

Other aspects of the invention provide for the inclusion of (a) inboundarticle conveyor means disposed relative to the spacer means to supply amoving array of discrete articles to the receiving zone thereof, and (b)outbound article conveyor means disposed relative to the spacer means toreceive a moving array of discrete articles from the discharge zonethereof, provided, that when the apparatus comprises two or more spacermeans, the inbound article conveyor supplies the receiving zone of theinitial upstream spacer means and the outbound article conveyor servicesthe discharge zone of the last downstream spacer means.

Still other aspects of the invention provide one or more of thefollowing features: the inbound and outbound conveyor means are eachcontinuously moving conveyor means; the transfer means havearticle-retaining surfaces which are convex in the orbital pathdirection; the transfer means are mounted on the orbital drive means atidentical fixed angular distances one from the other along the orbitalpath; and the orbital drive means is a continuous drive means forcontinuously orbiting the transfer means along the orbital path.

In another aspect of the invention, the orbital drive means and theradius adjusting means are dimensioned and configured so that the linearvelocity of the inbound conveyor means is substantially equal to that ofthe transfer means in the receiving zone of the spacer means which issupplied by the inbound conveyor means. Similarly, the linear velocityof the outbound conveyor means is substantially equal to that of thetransfer means in the discharge zone of the spacer means which isserviced by the outbound article conveyor means. In those cases in whichthe apparatus comprises two or more spacer means, the linear velocity oftransfer means in the discharge zone of an upstream spacer means issubstantially equal to the linear velocity of transfer means in thereceiving zone of the adjacent downstream spacer means.

Yet another aspect of the invention provides that the transfer meanshave respective leading sections and trailing sections and the grippermeans include first activatable gripper means disposed in the leadingsections and second activatable gripper means disposed in the trailingsections, the spacer means further including gripper control means toselectively activate and inactivate the first and second gripper meansindependently of each other. For example, the gripper control means maybe configured to inactivate in the discharge zone the first grippermeans before the second gripper means of a given transfer means, wherebythe portion of an article held by the first gripper means of a transfermeans is released in the discharge zone while the second gripper meansof the same transfer means retains its grip on another portion of thesame article.

The invention also provides for two or more of the spacer means to berespectively positioned with the discharge zone of relatively upstreamspacer means being located proximate to the receiving zone of theadjacent downstream spacer means, the respective spacer means beingconfigured and dimensioned to bring the orbital paths of theirrespective transfer means into leading section-to-leading sectionsynchronization.

The present invention also provides a method for changing the spacingbetween articles of a moving array of discrete articles, the methodcomprising the steps of: moving the article along at least one closed,non-circular orbital path passing through (i) a receiving zone in whichthe articles are maintained in a receiving zone orbital radius and (ii)a discharge zone in which the articles are maintained in a dischargezone orbital radius which is different from the receiving zone orbitalradius, with the orbital path distance between adjacent articles in thereceiving zone being maintained to be different from the orbital pathdistance between adjacent articles in the discharge zone; in thereceiving zone, transferring discrete articles from a first array ofinbound discrete articles to the orbital path and, in the dischargezone, transferring the discrete articles from the orbital path to asecond array of outbound articles, whereby the linear spacing betweenadjacent discrete articles deposited in the second array of articles isdifferent from the linear spacing between adjacent discrete articles inthe first array of articles.

The method aspects of the invention may also include one or more of thefollowing steps or sequence of steps: maintaining a discharge zoneorbital radius which is larger than the receiving zone orbital radiusand maintaining a fixed angular distance along the orbital path betweenadjacent transfer means whereby the orbital path distance betweenadjacent articles is greater in the discharge zone than in the receivingzone; continuously moving the articles along the orbital path;continuously moving both the first and second array of discretearticles; and transferring the discrete articles from the inbound arrayto the outbound array along two or more sequentially positioned orbitalpaths.

Other aspects of the present invention include moving the articles alongthe at least one orbital path by use of transfer means havingactivatable grippers thereon, and comprising the additional steps ofgripping the articles in the receiving zone by activating the grippermeans and releasing the articles in the discharge zone by thereininactivating the gripper means.

Yet another aspect of the method of the present invention includesinactivating the gripper means of a given transfer means in at least twostages to release a first, leading part of a given article whileretaining its grip on a second, trailing part of the same article untilthe first part of the article is transferred.

Other aspects of the invention will be apparent from the followingdescription of preferred embodiments thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, with some parts broken away and someomitted for clarity of illustration, of one embodiment of an apparatusof the present invention;

FIG. 2 is a schematic side view in elevation of the apparatus of FIG. 1;

FIGS. 2A, 2B and 2C show sequential relative operating positions of apair of synchronized transfer means of the two spacer means of theapparatus of FIG. 2; and

FIG. 3 is a partial cross-sectional view on an enlarged scale of atypical transfer shoe and part of the drum of the smaller of the twospacer means of the device of FIG. 1, the cross sections being takenperpendicularly to the axis of rotation of the drum.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIGS. 1 and 2 there is shown an apparatus generallyindicated at 10 for changing the spacing between articles 12 of a movingarray of discrete articles cut from a continuous web 14 travelling inthe direction indicated by the arrow associated therewith. In theembodiment illustrated in FIGS. 1 and 2, feed drum 18 comprises aninbound article conveyor means which supplies a moving array of discretearticles 12 to a first spacer means 20 from whence the articles 12 areconveyed to a second, larger diameter spacer means 30, thence todischarge drum 40 which, in the illustrated embodiment, provides anoutbound article conveyor means positioned relative to the second spacermeans 30 to receive a moving array of the discrete articles 12 from thedischarge zone (DZ' in FIG. 2) thereof. The respective directions ofrotations of feed drum 18, first spacer means 20, second spacer means 30and discharge drum 40 are indicated in FIGS. 1 and 2 by the arrows R₁₈,R₂₀, R₃₀ and R₄₀ respectively associated therewith. Receiving zone RZand discharge zone DZ of first spacer means 20 are defined by respectivesegments of the orbital path travelled by transfer means 34 of spacermeans 20. Similarly, receiving zone RZ' and discharge zone DZ' of secondspacer means 30 are defined by respective segments of the orbital pathtravelled by transfer means 34' of spacer means 30. A continuoustravelling substrate web 22 is fed, in the direction indicated by theunnumbered arrow associated therewith, about discharge drum 40 forplacement thereon of spaced-apart discrete articles 12. It will beapparent that substrate web 22 may, in certain embodiments of theinvention, be omitted and the discrete articles 12 placed inspaced-apart location directly upon discharge drum 40 for subsequentprocessing. However, in the illustrated embodiment the spaced-apartarticles 12 are placed upon substrate web 22 at a desired spacing in thedirection of travel between adjacent articles 12. The articles 12 mayoptionally be adhered to substrate web 22 by means of an adhesiveapplied in a selected pattern to the surface of substrate web 22 or byany other suitable means.

First spacer means 20 comprises (FIGS. 1 and 2) a drum 24 mounted forrotation by a pair of stub shafts, only one of which (stub shaft 26a) isvisible in the drawings. Stub shaft 26a and its counterpart (which iscoaxially aligned with stub shaft 26a and located at the oppositelateral end of drum 24) serve to mount drum 24 between a pair ofspaced-apart stanchions which, for clarity of illustration, are notshown in FIG. 1 but which are substantially the same as stanchions 28a,28b which serve to support drum 24' of second spacer means 30 in thesame manner as drum 24 is supported by its associated stanchions. Asbest seen in FIG. 2, three pairs of radially translatable support means32 extend through opposite circumferential faces of drum 24 and supportat their respective opposite ends respective ones of transfer meanscomprising, in the illustrated embodiment, transfer shoes 34. Transfershoes 34 are affixed by any suitable means such as bolts or the like torespective opposite ends of their associated support means 32 which, inthe illustrated embodiment of FIG. 2, comprise rigid rods mounted withinslide bearings 47 for sliding movement relative to drum 24. Obviously,other structures could be employed such as mounting each transfer shoe34 on its own radially translatable support means, such as a telescopingtube arrangement. Transfer shoes 34 may be rigidly mounted upon theradially translatable support means 32 or may be mounted for pivoting orrocking movement relative thereto in the direction of travel tofacilitate smooth transfer of articles 12. At the respective oppositelateral ends of each transfer shoe 34 there is provided a cam follower36a, 36b. As shown in FIG. 1, a pair of oval-shaped cam plates 38a, 38bare mounted in facing relationship on the respective inside faces ofstanchions 28a, 28b and the peripheral edges of cam plates 38a, 38bprovide respective peripheral edge cam tracks 42a, 42b (FIG. 1) alongwhich cam followers 36a, 36b respectively travel. The respective camtracks 42a, 42b are mirror images of each other and are aligned witheach other so that the paired cam tracks control radial movement oftransfer shoes 34 as described below. Stub shaft 26a and its counterpartrespectively pass through suitable openings in cam plate 38a, 38b andare journaled in suitable bearings (not shown) mounted on the stanchionssupporting drum 24.

A suitable drive means such as a motor M schematically indicated in FIG.2 is operatively connected through suitable gearing (not shown) to oneor both of stub shafts 26a and its counterpart for rotation of drum 24about its axis of rotation which is coincident with the longitudinalaxes of stub shafts 26a and its counterpart. (A similar drive means, notillustrated, may be provided for drums 24', 18 and 40.) Cam tracks 42aand 42b are eccentric relative to the axis of rotation of drum 24 sothat as the latter rotates to orbit transfer shoes 34, each connectedpair of transfer shoes 34 is radially translated by virtue of camfollowers 36a, 36b following their associated cam tracks 42a, 42b. Inthis way, each of the orbiting transfer shoes 34 orbits along anon-circular closed orbital path passing through a receiving zone RZ(FIG. 2) in which the transfer shoes 34 have a relatively small orbitalradius and a discharge zone DZ in which the transfer shoes 34 have arelatively large orbital radius. The cam tracks may have any suitableeccentric configuration so as to provide a desired different orbitalradius in each of the receiving zone RZ and discharge zone DZ of spacermeans 20 so as to provide between adjacent transfer shoes 34 a desiredorbital path distance PR in receiving zone RZ and a desired (larger, inthe illustrated embodiment) orbital path distance PD in discharge zoneDZ. As illustrated, support means 32 are radially translatable butangularly fixed relative to each other so that there is an equal, fixedangular distance between adjacent support means 32 and the transfershoes 34 carried thereon. The arrangement illustrated in FIG. 2 provides60° of angular distance between the respective longitudinal axes of eachof the six protruding support means 32.

The construction of second spacer means 30 may be similar or identicalto that of first spacer means 20 except that second spacer means 30 ispreferably of larger diameter than first spacer means 20 so that therespective orbital radii and orbital path distances between the transfershoes 34' are larger than those of transfer shoes 34. Accordingly, it isnot necessary to repeat in detail a description of second spacer means30 except to note that the various components thereof which correspondto those of first spacer means 20 are numbered identically thereto,except for the addition of a prime notation. It will be noted from FIG.2 that the receiving zone RZ' of second spacer means 30 is disposedadjacent the discharge zone DZ of first spacer means 20. First spacermeans 20 is thus considered the "upstream" spacer means and secondspacer means 30 the "downstream" spacer means, such designation beingapplied with regard to movement of the articles 12. The orbital pathdistance PR' between adjacent transfer shoes 34' of second spacer means30 in receiving zone RZ' thereof is greater than the orbital pathdistance PD between transfer shoes 34 in discharge zone DZ of secondspacer means 20. The orbital path distance PD' between adjacent transfershoes 34' of second spacer means 30 in the discharge zone DZ' thereof isstill greater and therefore substantially greater than the correspondingdistance PD in the discharge zone DZ of first spacer means 20. Theorbital path distance PR is very small or may even be zero, since thetransfer shoes 34 may be in substantially abutting contact in receivingzone RZ of first spacer means 20 in order to receive the abuttingarticles 12 cut from web 14. Utilization of the two spacer means 20 and30 provides a staged increase in the orbital path distances from PR toPD' in order to avoid the necessity for excessively long radialdistances to be travelled by a given transfer shoe 34 within the timeallowed by one-half of a complete rotation of its associated drum. Insome cases, a single spacer means will suffice to carry out the changein spacing and in other cases more than two spacer means may be used intandem, depending on the required change in spacing distances and speedof operation. In most cases, it is desired or necessary that theapparatus and its operation be arranged so that the linear velocities ofa transfer shoe and the member transferring an article to, or receivingan article from, the transfer shoe are substantially the same.

While a given transfer shoe 34 of spacer means 20 is within receivingzone RZ, gripping means thereon are actuated, as described in moredetail below, to grip and transport a discrete article 12 cut fromtravelling web 14. The orbital radius of the transfer shoe 34 carrying agiven article 12 is increased as the transfer shoe 34 rotates fromreceiving zone RZ into discharge zone DZ. In discharge zone DZ thetransfer shoe 34 having the article 12 thereon is brought into facingrelationship with a corresponding transfer shoe 34' of second transfermeans 30, as indicated by the sequence shown in FIGS. 2A and 2B.Transfer shoes 34, 34' of FIGS. 2A-2C are synchronized to meet in aleading edge-to-leading edge facing relationship (FIG. 2A) and to travelsynchronously through center-to-center (FIG. 2B) and trailingedge-to-trailing edge (FIG. 2C) facing relationship. Thus, reference torespective ones of transfer shoes 34 of spacer means 20 and transfershoes 34' of spacer means 30 being "synchronized" refers to at leastsufficient facing relationship as illustrated in FIGS. 2A-2C to enabletransfer of an article from one shoe to the other. At a positionintermediate those shown in FIGS. 2A and 2B the gripping meansassociated with transfer shoe 34 is at least partially released so thatarticle 12 may be grasped by the activated gripping means on transfershoe 34' for transfer thereto as indicated in FIG. 2C. Transfer shoes34' of second transfer means 30 receive the transferred articles 12 andorbit from receiving zone RZ' of second transfer means 30 to dischargezone DZ' thereof to deposit the articles 12 upon the travellingsubstrate web 22 in discharge zone DZ'. While traversing theirrespective orbital path segments shown in FIGS. 2A-2C, transfer shoes 34and 34' preferably have the same or nearly the same linear velocities inorder to facilitate transfer of articles 12. This can readily beprovided by selection of orbital velocity and orbital radius of thetransfer shoes 34, 34' while passing through, respectively, dischargezone DZ and receiving zone RZ'. Similarly, linear velocities of thesurfaces of feed drum 18 and discharge drum 40 are preferablyappropriately controlled to substantially equal those of, respectively,transfer shoes 34 in receiving zone RZ and transfer shoes 34' indischarge zone DZ'.

The respective gripping means holding articles 12 to transfer shoes 34'are inactivated in discharge zone DZ' whereby articles 12 are releasedand deposited upon substrate 22 (or, in the absence of a substrate web22, directly onto discharge drum 40.) Adhesive may be applied toarticles 12 and/or in an appropriate pattern onto substrate web 22 inorder to adhere article 12 firmly to substrate web 22. As shown in FIG.2, the travel path distance between adjacent articles 12 deposited uponsubstrate web 22 is indicated as a distance PD" because this distancemay be different from the orbital path distance PD' between adjacenttransfer shoes 34' in discharge zone DZ'. However, in the illustratedembodiment the periphery of drum 40 has substantially the same linearvelocity as transfer shoes 34' and articles 12 are substantially as long(in the direction of travel) as the transfer shoes 34' carrying them sothe distance PD' is equal to the distance PD". Obviously, if articles 12were shorter than the (leading edge-to-trailing edge) length of transfershoes 34' and centered thereon, the travel path distance betweenadjacent articles 12 would be PD' plus the difference in length betweenarticles 12 and their associated transfer shoes 34', assuming equalperipheral speeds of drum 40 and shoes 34'.

Referring now to FIGS. 1 and 3, the illustrated embodiment of thetransfer means comprises a typical transfer shoe 34 of spacer means 20having an article-retaining surface 46 which, as best seen in FIG. 3, isconvex in the orbital path direction, i.e., is convex in the directionof movement of transfer shoe 34 as it traverses its closed orbital path.(This orbital path direction of movement is indicated by the arrow OPDin FIGS. 1 and 3.) Article-retaining surface 46 has a leading section48a thereof comprising that portion of article-retaining surface 46which is between the longitudinal axis L--L (FIG. 1) and leading edge49a (FIG. 3) of transfer shoe 34. The remainder of the article-retainingsurface 46, between longitudinal axis L--L and trailing edge 49b, isconsidered to be the trailing section 48b of transfer shoe 34.

In the illustrated embodiment, the gripper means comprise ports ofpneumatic lines through which a vacuum may be selectively imposed. Thus,ports 50a (FIGS. 1 and 3) comprise first activatable gripper meansdisposed within leading section 48a and connected in pneumatic flowcommunication with a transfer means manifold 52a (FIG. 3) which in turnis connected to a bellows conduit 54a which extends from transfer meansmanifold 52a to a drum conduit 56a, which terminates in a connector port58a in a lateral side of drum 24 (FIGS. 1 and 3).

Referring jointly to FIGS. 1 and 3, a vacuum manifold 60a is connectedto a source of vacuum V (schematically illustrated in FIG. 3) tocontinuously maintain a vacuum within vacuum manifold 60a (and vacuummanifold 60b as described below). As seen in FIG. 1, vacuum manifold 60ais in the shape of a segment of a circle so that as drum 24 rotates aconnector port 58a associated with the activatable gripper means of theleading section 48a of a particular transfer shoe 34 will be inpneumatic flow communication with vacuum manifold 60a for a portion onlyof one complete revolution of drum 24, and will be isolated from vacuummanifold 60a for the remaining portion of each revolution. Thus, vacuummay be imposed upon ports 50a of transfer shoes 34 for only a selectedportion of each cycle of rotation by designing vacuum manifold 60a toencompass a selected segment of a complete circle. The interruptedsegment of vacuum manifold 60a is positioned in alignment with aselected portion of the rotational path of drum 24. Thus, when connectorport 58a illustrated in FIG. 1 is not aligned with vacuum manifold 60ait is exposed to the atmosphere and the ports 50a connected to theexposed connector ports 58a are not under vacuum. However, when a givenconnector port 58a is aligned with vacuum manifold 60a a vacuum ispulled thereon and thereby also upon the ports 50a associated therewithso that a gripping action is imposed on that portion of the article 12which overlies ports 50a.

Still referring to FIGS. 1 and 3, the vacuum connections for the ports50b located in the trailing section 48b of transfer shoe 34 are similaror identical to those for the ports 50a. That is, ports 50b are inpneumatic flow communication with the transfer means manifold 52 whichin turn is connected to a bellows conduit 54b, thence via a drum conduit56b to a connector port 58b in the lateral end of drum 24 which isopposite to that in which the connector ports 58a are disposed. A vacuummanifold 60b (FIG. 3) of similar construction to vacuum manifold 60a isconnected to the source of vacuum V as schematically indicated in FIG. 3so that when connector ports 58b are aligned with vacuum manifold 60b, avacuum is imposed upon ports 50b as described above. Vacuum manifolds60b (not visible in FIG. 1) are, like vacuum manifolds 60a, of aconstruction which defines an arcuate segment of a circle, less than acomplete circle, so that for a selected portion of its rotational path agiven connector port 58b is exposed to the atmosphere and not alignedwith vacuum manifold 60b. The interrupted segment of vacuum manifold 60bis, however, positioned out of register with the interrupted portion ofvacuum manifold 60a. In other words, as viewed along the longitudinalaxis of stub shafts 26a and its counterpart stub shaft (FIG. 1) thearcuate segments of vacuum manifolds 60a and 60b are out of alignmentone with the other along the rotational path of drum 24 so that theperiods of interruption of vacuum on, respectively, ports 50a and 50bare out of synchronization. In the illustrated embodiment, a connectorport 58a associated with the leading section 48a of a given transfershoe 34 will clear its associated vacuum manifold 60a before theconnector port 58b associated with the trailing section 48b of the sametransfer shoe 34 clears its vacuum manifold 60b. In this manner, asillustrated in FIG. 2B, the gripping action imposed by ports 50a of agiven transfer shoe 34 on the article 12 carried thereon is releasedwhile the gripping action maintained on the same article 12 by the ports50b of the same transfer shoe 34 is maintained. This main control ofeach article 12 by transfer shoe 34 while the gripping force imposed bythe leading section of transfer shoe 34' is being established. Only thenis the gripping force imposed by the trailing section 48b of transfershoe 34 released to complete the transfer from transfer shoe 34 totransfer shoe 34', as illustrated in FIG. 2C. In this manner, positivecontrol is maintained over the articles 12 at all times during thetransfer process since there is no time at which the articles 12 arefree of the gripping action provided by one or the other of the transfershoes 34, 34'.

Generally, rotation of spacer means 20 and 30 and of drums 18 and 40 ispreferably continuous rather than intermittent, and more preferably iscontinuous and of constant rotational velocity to avoid the necessity ofaccelerating and decelerating the apparatus. Thus, the spacer means, orat least the drums 24 and 24' thereof, preferably continuously rotate atconstant rotational velocities. The linear velocity of the transfershoes 34 and 34' along their respective orbital paths will of coursevary directly with their orbital radius. Drums 18 and 40 or equivalentconveyor belts or the like will likewise preferably have continuous,constant linear velocities. As noted above, dimensions and rotationalspeeds of the components of the apparatus will preferably be designed tomatch linear velocities of receiving and discharging members in theirrespective receiving and discharge zones.

Those skilled in the art will recognize that numerous details ofconstruction embodying well-known machine design expedients have beeneliminated or not described for clarity and simplicity of illustration.For example, a wear plate would normally be provided between drum 24 andstationary vacuum manifolds 60a and 60b. It will further be appreciatedthat the apparatus of the invention can utilize one or, alternatively,can utilize two, three or more spacer means in tandem, depending on thedesired difference in spacing between received and discharged articlesand operating speeds. It will further be appreciated that theillustrated direction of rotations of the two illustrated spacer means20 and 30 and of drums 18 and 40 could be reversed so that articlesreceived in an array of spaced-apart articles could be placed in closerproximity to each other, including abutting or even overlappingrelationship to each other. It will further be appreciated that one orboth of the feed drum 18 and discharge drum 40 could be replaced by anyother suitable conveyor means, such as an endless belt or the like.

While the invention has been described in detail with respect tospecific preferred embodiments thereof, it will be appreciated by thoseskilled in the art that numerous alterations and embodiments thereto mayreadily be conceived upon a reading and understanding of the foregoingand that such alterations and embodiments will nonetheless lie withinthe scope of the invention and the appended claims.

What is claim is:
 1. Apparatus for changing the spacing between articlesof moving array of discrete articles, comprising at least one spacermeans comprising:an orbital drive means including a rotatable drumhaving a plurality of transfer means mounted thereon for orbiting of thetransfer means along a closed orbital path passing through a receivingzone and a discharge zone; gripper means on the transfer means effectiveto grasp discrete articles in the receiving zone and to release thediscrete articles in the discharge zone; and radius-adjusting meansoperatively connected to the transfer means to selectively adjust theorbital radius thereof between a receiving zone radius and a dischargezone radius which is different from the receiving zone radius, theradius-adjusting means comprising (a) a plurality of support meansreciprocatively disposed through the rotatable drum, each reciprocativesupport mens supporting on its opposite ends a diametrically-opposedpair of transfer means, (b) a cam plate member having a cam trackthereon and being disposed near an end of the rotatable drum, (c) eachtransfer means including a cam follower member movable along the camtrack upon rotation of the rotatable drum, whereby a pair ofdiametrically-opposed transfer means are radially reciprocated togetherby the movement of their respective cam follower members along the camtrack, such that the closed orbital path is a non-circular orbital pathand the orbital path distance between adjacent transfer means in thereceiving zone is different from the orbital path distance betweenadjacent transfer means in the discharge zone.
 2. The apparatus of claim1 comprising at least two spacer means respectively positioned with thedischarge zone of one of the spacer means being located proximate to thereceiving zone of the other spacer means.
 3. The apparatus of claim 1wherein the cam track of the radius-adjusting means of the at least onespacer means is dimensioned and configurated to adjust its orbitalradius to provide a discharge zone radius which is larger than itsreceiving zone radius, whereby the orbital path distance betweenadjacent transfer means for a spacer means is greater in its dischargerzone than in its receiving zone.
 4. The apparatus of claim 1 furtherincluding (a) inbound article conveyor means disposed relative to thespacer means to supply a moving array of discrete articles to thereceiving zone thereof, (b) outbound article conveyor means disposesdrelative to the spacer means to receive a moving array of discretearticles from the discharge zone thereof.
 5. The apparatus of claim 4wherein the orbital drive means and the radius-adjusting means aredimensioned and configured so that the linear velocity of the inboundconveyor means is substantially equal to that of the transfer means inthe receiving zone of the spacer means which is supplied by the inboundconveyor means and the linear velocity of the outbound conveyor means issubstantially equal to that of the transfer means in the discharge zoneof the spacer means which is serviced by the outbound conveyor means. 6.The apparatus of claim 4 wherein the inbound and outbound conveyor meansare each continuously moving conveyor means.
 7. The apparatus of claim 1wherein the transfer means are mounted on the orbital drive means atidentical fixed angular distances one from the other along the orbitalpath.
 8. The apparatus of claim 1 wherein the orbital drive means is acontinuous drive means for continuously orbiting the transfer mens alongthe orbital path.
 9. The apparatus of claim 1 wherein the transfer meanshave respective leading sections and trailing sections and the grippermeans include first activatable gripper means disposed in the leadingsections and second activatable gripper means disposed in the trailingsections, the spacer means further including gripper control means toselectively activate and inactivate the first and second gripper meansindependently of each other.
 10. The apparatus of claim 9 wherein thegripper control means are configured to inactivate in the discharge zonethe first gripper means before the second gripper means of a giventransfer means, whereby the portion of an article held by the firstgripper means of a transfer means is released in the discharge zonebefore the portion of that article held by the second gripper means ofthe same transfer means.
 11. The apparatus of claim 10 wherein thetransfer means have article-retaining surfaces which are convex in theorbital path direction.
 12. The apparatus of claim 11 comprising atleast two spacer means respectively positioned with the discharge zoneof one of the spacer means being located proximate to the receiving zoneof the other spacer means, the respective spacer means being configuredand dimensioned to bring the orbital paths of their respective transfermeans into leading section-to-leading section synchronization.
 13. Theapparatus of claim 4 further comprising a second spacer means, theinbound article conveyor supplying the receiving zone of one of thespacer means and the outbound article conveyor means servicing thedischarge zone of the other spacer means.
 14. The apparatus of claim 5further comprising a second spacer means including transfer meansthereon, the linear velocity of transfer means in the discharge zone ofone of the spacer means being substantially equal to the linear velocityof transfer means in the receiving zone of the other spacer means. 15.Apparatus for changing the spacing between articles of a moving array ofdiscrete articles, comprising at least one spacer means comprising:acontinuous orbital drive means carrying thereon one or more radiallytranslatable supports having transfer means mounted thereon forcontinuous orbiting of the supports and their associated transfer meansalong a closed orbital path passing through a receiving zone and adischarge zone, the transfer means being mounted on the orbital drivemeans at identical fixed angular distances on from the other along theorbital path, each radially translatable support having on its oppositeends a diametrically-opposed pair of transfer means, selectivelyactivatable gripper means on the transfer means effective to graspdiscrete articles in the receiving zone and to release the discretearticles in the discharge zone; radius-adjusting means operativelyconnected to the radially translatable supports to selectively adjustthe orbital radius of the transfer means mounted thereon between areceiving zone radius and a discharge zone radius which is differentfrom the receiving zone radius, whereby the closed orbital path is anon-circular orbital path and the orbital path distance between adjacenttransfer means in the receiving zone is different from the orbital pathdistance between adjacent transfer mean in the discharge zone.
 16. Theapparatus of claim 15 wherein the transfer means have respective leadingsections and trailing sections and include first activatable grippermeans disposed in the leading sections and second activatably grippermeans disposed in the trailing sections, the spacer means furtherincluding gripper control means configured to inactivate in thedischarge zone the first gripper means before the second gripper meansof a given transfer means, whereby the portion of an article held by thefirst gripper means of a transfer means is released in the dischargezone before the portion of that article held by the second gripper meansof the same transfer means.
 17. The apparatus of claim 16 wherein thetransfer means have article-retaining surfaces which are convex in theorbital path direction.
 18. The apparatus of claim 16 wherein theorbital drive means comprises a rotatable drum on which theradially-translatable supports are mounted.
 19. The apparatus of claim17 wherein the gripper means comprise pneumatic line ports in thearticle-retaining surfaces.
 20. The apparatus of claim 17 furthercomprising a second spacer means including transfer means thereon, thespacer means being configured and dimensioned to bring the orbital pathsof their respective transfer means into leading section-to-leadingsection synchronization.